Saw-drive.



No. 812,863. PATENTED FEB. 20, 19 06. W. LEWIS. SAW DRIVE.

APPLICATION FILED 13150.17, 1904.

2 SHEETS-SHEET 1.

PATENTED FEB. 20, 1906.

2 SHEETS-SHEET '2.

W. LEWIS. SAW DRIVE.

APPLICATION FILED DEO.17, 1904.

INVENTOR.

w/r Essa.- v2

4 TTU/MEY.

WILFRED LEWIS, OF PHILADELPHIA, PENNSYLVANIA.

' SAW-DRIVE.

Specification of Letters Patent.

Patented Feb. 20, 1906.

Application filed December 1'7. 1904. Serial No. 237,221-

To all whom it may concern.-

Be it known that I, WILFRED LEWIS, a citizen of the United States ofAmerica, residing in the city and county of Philadelphia, in the Stateof Pennsylvania, have invented a certain new and useful Improvement inSaw- Drives, of which the following is a true and exact description,reference being had to the accompanying drawings, which form a partthereof.

My invention relates to driving mechanism for rotary saws, and has forits object to provide for driving such saw-blades by a series ofprogressive impulses communicated to the blade at or near its peripheryand in such manner as to avoid lateral thrust against the saw-bladewhich would tend to press it out of alinement.

The nature of my improvementswill be best understood as described inconnection with the drawings in which they are illustrated, and inwhich- Figure 1 is a plan View of a saw-drive embodying my invention inwhat I consider to be its best and most efficient form. Fig. 2 is a sideelevation of the same mechanism; Fig. 3, a transverse section through aportion of the blade and through the latch and latchholding mechanism,as shown in Figs. 1 and 2. Fig. 4 is a plan view illustrating amodification of my invention; Fig. 5, a side elevation illustratinganother modification; Fig. 6,

a front elevation of a portion of the mechanism shown in Fig. 5, andFig. 7 a side elevation illustrating still another modification of myinvention.

Aindicates the base or bed plate, to which the frame proper of the sawand saw-driving mechanism is attached.

B is the frame, and, referring first to the construction shown in Figs.1 to 3, C isa shaft actuated through a pulley C and communicating motionthrough gear-wheels C and C to the driving-shaft C which has formed onor attached to it the oppositelyextending cranks, (indicated at C andC.)

C is the shaft on or to which the saw-blade K is secured.

D and D are connecting-rods secured to the crank C and extendingtherefrom in opposite directions, being pivotally attached at theirother ends to the oscillating arms D and D pivoted so as to rotate onthe axis of the saw-blade and extending therefrom, so

as to engage the angularly-disposed connecting-rod on the opposite sideof the saw-blade.

The connecting-rods E and E, secured on the crank C, connect withoscillating arms E and E of substantially the same character as the armsD and D The oscillating arms D and D have secured to them thelatchholding bosses F and F, while the arms E and E have secured to themthe similar bosses G and-G. The construction of these bosses is similarand is shown in Fig. 3, each boss supporting a latch H, having a grooveH at one side and a projecting guide-pin H extending from its rear end,its front end being beveled, as indicated at H I indicates a pinextending through the side of the boss into the groove H and serving toprevent the rotation of the latch, and also it escapes from the cavityin the boss. J

indicates a spring which tends to force the latch outward.

The saw-blade K is provided near to but within its periphery with anannular series of perforations K K, preferably beveled at one side, asindicated at K It is of course obvious that as each of the oscillatingarms moves forward or in the direction of the saw of Fig. 2 the latch Hwill enter one of the perforations K, and if the arm is moving with thesame or greater speed than the saw-blade will engage and drive the bladeuntil by reason of the reversal of motion of the arm or its decrease inspeed the bevel-latch will ride up out of the perforation on the rearside thereof and move downward to again engage the sawblade during asuccessive forward movement. By providing a number of oscillating armsand actuating them so that they move in the same direction at differenttimes, as is the case in the construction described, a more or lessproximation to a continuous drive can be secured, and I believe that thetwo-crank four-armed mechanism described in connection with Figs. 1 and2 is especially well adapted to provide for a sufficiently even movementof the saw-blade.

It will be noticed that the described device engages and drives thesaw-blade without ex erting any appreciable lateral thrust upon it, andthis is a feature to which I'attach much importance.

In the modification shown in Fig. 4 a single crank (indicated at C isattached to the driving-shaft C and connected, through connecting-rods Dand E with oscillating arms I) and E situated on opposite sides of thesaw-blade K and provided with latch-carrying bosses, as in the case ofthe oscillating though less continuous and and the arm Q on the otherside.

arms of the before-described construction. This is a practicalmodification of my drive,

perfect in its operation than the four-armed construction.

In Figs. 5 and 6 I have indicated a modification of my driving mechanismin which the sawblade does not require to be perforated. As shown, thedriving-shaft C is provided with a crank C", to which are secured theangularly-extending connecting-rods D and E, On the axis or shaft C ofthe saw are pivotally secured arms L L, the said arms extending upalongside of the saw-blade on one side and over the edge of the saw, asindicated at L, and terminating in abutment-surfaces U, which lie closeto the blade of the saw. The arms are provided with internally-threadedbosses L in which screw clamping-screws M, the nuts M of which areadapted to come in contact with the saw-blade directly opposite to theabutment ends L of the swinging arms. A link N is secured to each screw,as shown, and connected with one of the rods D or E". In thisconstruction the connecting-rods are moving in the direction of themotion of the saw. They act first on the connecting-rods N and throughthem on the screws M, turning the screws until they come in contact withthe saw-blade and clamp it between their ends and the abutments LThereafter the motion of the crank commu nicated through theconnecting-rod carries the swinging arm of the saw-blade forward until areversal of motion occurs or until the saw-blade through other drivingattachments begins to move faster than the swinging arm, when the dragof the connecting-rod results first in such shifting of the link N aswill move the screws to unclamp the saw-blade and afterward in areversed motion of the swinging arm.

In the construction shown in Fig. 7 the frame B is provided with anextension B, which support a series of drive-shafts O, O, and 0connected together by gear-wheels (indicated at O O and O and eachprovided with a crank, as indicated at O O and 0 From these cranksconnecting-rods P, P, and P extend to connections with the swinging armsQ, Q, and Q The arms Q and Q are shown on one side of the saw-blade Eacharm is provided with a latch-boss F, as indicated, and it will readilybe seen that in this construction a very similar drive action is securedto that shown and described in connection with Figs. 1 and 2.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. Driving mechanism for rotarysaw blades having in combination anoscillating arm swinging on the axis of the saw, means for oscillatingsaid arm and a clutch on said 1 arm arranged to engage the saw-bladenear but within its periphery when the arm moves in one direction and todisengage the sawblade when the arm moves in the other direction.

2. Driving mechanism for rotarysaw blades having in combination aplurality of oscillating arms swinging on the axis of the saw, means foroscillating said arms, as described and so that they move in the samedirection at different times, and a clutch on each said arm arranged toengage the saw-blade near but within its periphery when the arm moves inone direction and to disengage the saw-blade when the arm moves in theother direction.

3. Driving mechanism for rotary saw blades having in combination anoscillating arm swinging on the axis of the saw, means for oscillatingsaid arm, and a clutch on said arm arranged to engage the saw-bladewithout lateral thrust and near but within its periphery-when the armmoves in one direction and to disengage the saw-blade when the arm movesin the other direction.

4. Driving mechanism for rotary-saw blades having in combination asaw-blade having near its periphery an annular series of transverseperforations, an oscillating arm swinging on the axis of the saw-blades,means for oscillating said arm and a spring-latch H, carried by the armin position to register with and engage the perforations in thesaw-blade as described.

5. Driving mechanism for rotary-saw blades having in combination asaw-blade having near its periphery an annular series of transverseperforations, a plurality of oscillating arms swinging on the axis ofthe sawblade, one or more of said arms being situated on one side of thesaw and one or more on the other side, means for oscillating said armsand a spring-latch H, carried by each arm in position to register withand engage the perforations in the saw-blade as described.

6. Driving mechanism for rotary-saw blades having in combination twooscillating arms pivoted on the axis of the saw-blade on each sidethereof, a driving-shaft having two oppositely-extending cranks, twoconnectingrods extending in different directions from each crank andconnecting with the oscillating arms as described so as to move the twoarms on the same side of the blade at differenttimes in the samedirection, and a clutch on each swinging arm arranged to engage anddrive the saw-blade when moved in one direction and to disengage theblade when moved in the opposite direction.

I/VILFRED LEWIS.

Witnesses:

ARNOLD KATZ, L. STEWART.

